Safety-lamp



N. A. AUERT. SAFETY LAMP.

APPLICATION HLED SEPT. s. 1920. 1,376,243.

Patented Apr. .Y 26, 1921.

. UNITED STATES PATENT oFFlcE.

NICHOLAS ALBERT AUERT, 0F LONGMONT, COLORADO, ASSIGNOR 0F ONE-.HALF TO CLAUS H. LEHBANK, OF LONGMONT, COLORADO.

SAFETY-LAMP.

Specification of Letters Patent.

Application led September 8, 1920. Serial No. 408,904.

To all w /fo in t may concern:

Be it known that I, NroHoLAsA'. AUERT, a citizen of the United States, residing at Longmont, in the countyr of Boulder and State of Colorado, have invented certain new and useful Improvements in Safety-Lamps, of which the following is a specification.

i This invention relates to incandescent electric lamps specially adapted for use in mines which are liable to contain inflammable gasesA` and for use in other similar places; and it consists inthe novel construction and combination of the parts hereinafter fully described and claimed whereby the electric current is cut olf and the lamp is extinguished when an exposed .frangible globe which incloses the lamp is broken, and before the lamp itself is broken, and before the incandescent filament has been able to ignite the gas.

In the drawings, Figure 1 is a vertical section through a lamp constructed according to this invention. Fig. 2 is a plan view of the same.

The base 23 of the lamp has a tubular portion 21 on one side in which the electric line wires 1.4; are secured. One wire is connected to the base by a screw 13 and the other wire has a terminal 22 at its end. The base 23 has a socket 24 on its upper side, and a gi'lide cylinder l is provided having a screw-threaded tubular stem 25 which is screwed into the socket 24:, so that a chamber 26 for a spring 16 is formed inside the base. This chamber has a projecting lip 27 at its bott-om, and a plate 2O of insulating material is arranged to rest on this lip.

An 'eyclet 19 is arranged in the plate 20, and the terminal 22 of the line wire is arranged to project through this eyelet at the center of the chamber 26.

A disk 28 is arranged to slide vertically in the cylindrical guide 1, and it has a frangible or brittle glass globe 4 secured to it and inclosing an incandescent electric lamp 5.

This incandescent lamp is provided with a glass bulb and is of any approved construction, and its socket 7 is screwed into a hole in the center of the disk 28, and is provided with a terminal 29. One leading in wire of the lamp is connected to the terminal 29, and the other to the socket 7, in the the usual manner.

A plate 17 of insulating material is arranged to rest on the bottom of the cylindrical guide 1, and the disk 28 rests on the head of a contact screw 8 which is carried'4 Patented Apr. 26, 1921.

current passes from the battery or otherv source of electricity to the filament of the lamp. Stop screws 8 are -screwed into the bottom of the cylindrical guide 1, and project through holes in the insulating plate j 17, and their heads limit theupward movement of this plate and the disk 28 in the cylindrical guide. Y

An'adjustable ring 2 is screwed onto the cylindrical guide 1, and carries a protecting cage 3 of wire, which incloses the glass globe 4L. A cushion 6 is provided at the top of the cage 3 which bears on the top of the glass globe 1, and normally holds the slidable parts in their depressed positions as shown, with the contact spring 15 bearing on the terminal 22 of the line wire.

The helical spring 16 is arranged between the two plates of insulating material 20 and 17, and is normally compressed. When any accident occurs which breaks the glass globe a, the spring 16 forces the upper plate 17 upwardly, and raises the contact spring l5 out of engagement with the terminal 22, thereby breaking the circuit and extinguishing the incandescent filament before its bulb is broken, and before it has been able to ignite any inflammable gas.

The adjustable ring 2 is provided with a suitable locking screw 30 which engages and operating normally to hold the lamp in circuit, a vertically adjustable ring secured to the said guide and operating to adjust the pressure of the retaininof device on the lamp globe, means for completing the lam circuit when the said disk is in its norma position, and means for sliding the disk automatically in its guide, when the lamp globe is broken, so as to break the circuit.

2. In a safety lamp, a supportinof base providedV with a guide, a disk sudole in the guide, an electric lamp and a frangible lamp globe carried by the said disk, a retaining device arranged between the lamp globe and the base and operating normally to hold the lamp in circuit, an insulating plate supporting the said disk in the guide, means for limitlng the sliding movement of the insulating plate, contact devices for the lamp carried by the said insulating plate, and a spring which slides the insulating plate and the said disk in the guide and thereby breaks the circuit when the lamp globe is broken.

3. In a safety lamp, a supporting base provided With a guide, superposed insulating plates arranged in the said base and guide, a disk slidable in the said guide and supported by the upper insulating plate, an electric lamp and a frang'ible lamp globe carried by the said disk, a retaining device arranged between the lamp globe and the base and operating to normally hold the lanip in circuit, means for completing the lamp circuit when the said disk and upper insulating plate are in their normal positions, and a spring arranged between the two insulating plates and operating to slide the upper insulating late and the said disk in the guide so as to reak the circuit when the lamp globe is broken.

4. In a safety lamp, a supporting base provided With a socket which forms a chamber, a guide provided with a stem which is secured to the said socket, insulating plates arranged in the said guide and chamber, a disk slidable in the said guide, an electric lamp carried by the said disk, a spring arranged between the two said plates in the said chamber and operating to slide the disk in the guide and break the lamp circuit, a frangible globe secured to the disk and inclosing the said lamp, an adjustable ring engaging with the said guide, a wire cage secured to the said ring and inclosing the said globe, and a cushion arranged between the cage and the globe, the said sprin bein" normally held in compression by t e said globe and cage with the lamp in circuit until the said globe is broken.

In testimony whereof I have affixed my signature.

NICHOLAS ALBERT AUER/I. 

